An LED (light-emitting diode) light engine is a device including at least one LED module and an LED driver (also referred to as electronic control gear (ECG)). The LED light engines are widely used in various applications such as indicators, signs, luminaires, LCD (liquid crystal display) backlights, automobile headlights, medical devices, and optical communications.
One challenge for the LED lighting technology is to use dimming controller (also referred to as light controller) mechanism to control the light output level of the LED lighting. Pulse-width modulation (PWM) can be used for dimming the LED lighting. The PWM dimmer can include electronic circuitry that suppresses current flow for the LED lighting during defined portions of each cycle of the voltage waveforms. The brightness of light emitted by the LED lighting is adjusted by setting at what voltage (hence, what phase) in the half-cycle the dimmer begins to provide electric current to the LED lighting.
However, the pulses generated by conventional digital PWM light controllers have too large of step sizes for duty cycles. A digital processor of the digital PWM light controller generates waveforms with defined duty cycles. Due to the hardware limitation of the digital processor, the duty cycles can only change in discrete steps. When a light dimmer adjusts light intensity of the LED lighting using the conventional digital PWM light controller, the light intensity is dimmed in steps that are noticeable to human eyes, rather than decreases smoothly. The discrete steps in dimming light intensity are inherent in the conventional digital PWM light controller due to the processor limitation.